Charge controller

ABSTRACT

A charge controller including: an environment prediction part that predicts, during charging of a battery mounted on a vehicle, a state of an external environment of the vehicle after an end of charging; a target temperature setting part that sets a target temperature of the battery at the end of charging on the basis of the state of the external environment predicted by the environment prediction part; and temperature adjusting part that adjusts a temperature of the battery during the charge such that the temperature of the battery becomes the target temperature set by the target temperature setting part at the end of charging.

TECHNICAL FIELD

The present invention relates to a charge controller.

BACKGROUND OF THE INVENTION

A vehicle is equipped with a charge controller that controls charging ofa battery. Patent Document 1 discloses a technique of charging a batterywhile adjusting a battery temperature. Specifically, charging of thebattery is controlled such that the battery is at temperatures at whichthe battery discharges easily.

PRIOR ART Patent Document

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2005-117727

BRIEF DESCRIPTION OF THE INVENTION Problem to be Solved by the Invention

When the battery is left unattended after charging, the batterytemperature may change due to the influence of an external environment,which may adversely affect the battery. For example, the batterydeteriorates when the battery temperature becomes high, and anabnormality may occur when the battery is used at low temperatures. Theabove-described technique of Patent Document 1 cannot adjust thetemperature of the battery after charging.

The present invention focuses on this point, and its object is toprevent or reduce adverse effects on a battery after charging.

Means for Solving the Problem

A first aspect of the present invention provides a charge controllerincluding: an environment prediction part that predicts, during chargingof a battery mounted on a vehicle, a state of an external environment ofthe vehicle after an end of charging; a target temperature setting partthat sets a target temperature of the battery at the end of charging onthe basis of the state of the external environment predicted by theenvironment prediction part; and a temperature adjusting part thatadjusts a temperature of the battery during the charge such that thetemperature of the battery becomes the target temperature, set by thetarget temperature setting part, at the end of charging.

The environment prediction part may predict a change in an outside airtemperature after the end of charging as the state of the externalenvironment, and the target temperature setting part may set the targettemperature on the basis of the change in the outside air temperature.

The environment prediction part may predict a magnitude of the change inthe outside air temperature after the end of charging, and the targettemperature setting part may set the target temperature within apredetermined temperature zone according to the magnitude of the changein the outside air temperature.

The target temperature setting part may set the target temperature lowerthan a predetermined value when the environment prediction part predictsthat the temperature of the battery will rise after the end of charging,and set the target temperature higher than the predetermined value whenthe environment prediction part predicts that the temperature of thebattery will decrease after the end of charging.

The target temperature setting part may set the target temperature to atemperature at a lower limit in a predetermined temperature zone whenthe environment prediction part predicts that the temperature of thebattery will rise after the end of charging, and set the targettemperature to a temperature at an upper limit in the temperature zonewhen the environment prediction part predicts that the temperature ofthe battery will decrease after the end of charging.

The charge controller may further includes a storage that storesenvironment information indicating a state of past external environment,and the environment prediction part may predict a state of an externalenvironment after an end of charging on the basis of the environmentinformation stored in the storage.

Effect of the Invention

According to the present invention, it is possible to prevent or reduceadverse effects on a battery after charging.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an example of a configurationof a vehicle 1 equipped with a charge controller.

FIG. 2 is a block diagram illustrating an example of a configuration ofa charge controller 10.

FIG. 3 is a schematic diagram for illustrating an example of setting atarget temperature of a battery 2.

FIG. 4 is a flowchart showing an example of a charging process for thebattery 2.

DETAILED DESCRIPTION OF THE INVENTION <Configuration of a ChargeController>

A charge controller is mounted on a vehicle, for example, and controlscharging of a battery provided in the vehicle.

FIG. 1 is a schematic diagram illustrating an example of a configurationof a vehicle 1 equipped with the charge controller. The vehicle 1 is anelectric vehicle (EV), for example. As shown in FIG. 1 , the vehicle 1includes a battery 2, a generator 4, and a charge controller 10. In FIG.1 , as a matter of convenience, other components of the vehicle 1 areomitted.

The battery 2 is an EV battery. The temperature of the battery 2 is notconstant and may change after the end of charging. For example, thetemperature of the battery 2 rises when the external temperature of thevehicle 1 rises, and decreases when the external temperature decreases.

The generator 4 is a motor electrically connected to the battery 2 andsupplies electric power to the battery 2, for example. The battery 2 ischarged by the supply current flowing from the generator 4 to thebattery 2.

The charge controller 10 controls charging of the battery 2. The chargecontroller 10 controls charging of the battery 2 by controlling thesupply current flowing from the generator 4 to the battery 2, forexample. Although details will be described later, the charge controller10 of the present embodiment adjusts the temperature of the battery 2during the charge such that the temperature of the battery 2 at the endof charging becomes a target temperature set on the basis of a state ofthe external environment predicted during charging. By doing this, thetemperature of the battery 2 at the end of charging reflects the stateof the external environment, and therefore it is possible to prevent thebattery 2 from being adversely affected by the external environmentafter the end of charging.

In the above description, the battery 2 is charged by receiving a powersupply from the generator 4, but the present invention is not limited tothis. For example, the battery 2 may be charged by receiving power froma charger outside the vehicle 1. Even in this case, the chargecontroller 10 controls charging of the battery 2 by controlling thecurrent from the charger.

[Detailed Configuration of the Charge Controller 10]

A detailed configuration of the charge controller 10 will be describedwith reference to FIG. 2 .

FIG. 2 is a block diagram illustrating an example of a configuration ofthe charge controller 10. As shown in FIG. 2 , the charge controller 10includes a storage 12, a communication part 13, and a control part 14.

The storage 12 includes a read only memory (ROM) and a random accessmemory (RAM), for example. The storage 12 stores various types of dataand programs to be executed by the control part 14. For example, thestorage 12 stores environment information indicating a state of pastexternal environment.

The communication part 13 communicates with a device provided outsidethe vehicle 1. The communication part 13 transmits and receivesinformation to and from an external server 8. For example, thecommunication part 13 receives real-time weather information from theexternal server 8. The weather information is information ontemperature, sunshine duration, weather, and the like, for example. Theweather information received from the external server 8 may be stored inthe storage 12.

The control part 14 is a central processing unit CPU), for example. Thecontrol part 14 performs a process of charging the battery 2 byexecuting the program stored in the storage 12. In the presentembodiment, the control part 14 functions as an environment predictionpart 142, a target temperature setting part 143, a temperature detectionpart 144, and a temperature adjusting part 145.

The environment prediction part 142 predicts a state of the externalenvironment of the vehicle 1. The environment prediction part 142predicts, during charging of the battery 2, a state of the externalenvironment after the end of charging. For example, the environmentprediction part predicts a state of the external environment for apredetermined time (e.g., 8 hours to 24 hours) from the end of charging.The environment prediction part 142 predicts, as the state of theexternal environment, a change in an outside air temperature after theend of charging of the battery 2. For example, the environmentprediction part 142 predicts whether the outside air temperature willrise or decrease after the end of charging of the battery 2. Theenvironment prediction part 142 may predict the degree of change in theoutside air temperature within a predetermined time period from the endof charging.

The environment prediction part 142 may predict a state of the externalenvironment by acquiring the weather information from the externalserver 8 in real time. That is, the environment prediction part 142 maypredict the state of the external environment based on the weatherinformation which the communication part 13 received from the externalserver 8 in real time. By acquiring the weather information in realtime, the state of the external environment after the end of chargingcan be accurately predicted.

The environment prediction part 142 may predict a state of the externalenvironment after the end of charging, on the basis of the environmentinformation indicating the state of past external environment stored inthe storage 12. By doing this, when the weather information cannot beacquired from the external server 8, the state of the externalenvironment after the end of charging can be estimated by referencingthe environment information of the same time of day in the past.

The target temperature setting part 143 sets a target temperature of thebattery 2 at the end of charging. The target temperature setting part143 sets the target temperature of the battery 2 in consideration of astate of the external environment when the battery 2 is left unattendedafter the end of charging. Here, the target temperature setting part 143sets the target temperature of the battery 2 at the end of charging onthe basis of the state of the external environment that has beenpredicted by the environment prediction part 142.

FIG. 3 is a schematic diagram for illustrating an example of setting thetarget temperature of the battery 2. Here, a temperature zone of thebattery 2 is divided into an appropriate temperature zone, a hightemperature zone, and a low temperature zone. The appropriatetemperature zone is temperature in the range of 0° C. to 40° C., forexample. The high temperature zone is a temperature zone higher than 40°C. and the low temperature zone is a temperature zone lower than 0° C.In the appropriate temperature zone, the battery 2 is less likely todeteriorate and functions normally. In the high temperature zone, thebattery 2 tends to deteriorate due to high temperature. In the lowtemperature zone, precipitation tends to occur when the battery 2 ischarged. Therefore, the target temperature setting part 143 sets thetemperature in the appropriate temperature zone (0° C. to 40° C.) of thebattery 2 as the target temperature.

The target temperature setting part 143 sets the target temperature onthe basis of a change in an outside air temperature after the end ofcharging of the battery 2. This enables setting of a target temperatureunder the assumption that the battery 2 after the end of charging willbe affected by the outside air temperature. In other words, the targettemperature setting part 143 can set, as the target temperature, atemperature in the above-described appropriate temperature zone that canreduce the influence of the outside air temperature.

When the environment prediction part 142 predicts that the temperatureof the battery 2 will rise after the end of charging, the targettemperature setting part 143 sets the target temperature lower than apredetermined value. For example, the target temperature setting part143 sets a temperature at the lower limit (close to 0° C.) in theabove-described appropriate temperature zone as the target temperature.On the other hand, when the environment prediction part 142 predictsthat the temperature of the battery 2 will decrease after the end ofcharging, the target temperature setting part 143 sets the targettemperature higher than the predetermined value. For example, the targettemperature setting part 143 sets a temperature at the upper limit(close to 40° C.) in the appropriate temperature zone as the targettemperature. This facilitates maintaining the temperature of the battery2 in the appropriate temperature zone even when the outside airtemperature rises or decreases after the end of charging. Thepredetermined value is a median value (20° C.) of the appropriatetemperature zone, for example.

The target temperature setting part 143 may set the target temperaturewithin a predetermined temperature zone according to the magnitude ofthe change in the outside air temperature. For example, the targettemperature setting part 143 sets 0° C., which is in the appropriatetemperature zone, as the target temperature when it is predicted thatthe outside air temperature will increase significantly, and sets 15°C., which is in the appropriate temperature zone, to the targettemperature when it is predicted that the outside air temperature willincrease slightly.

The temperature detection part 144 detects the temperature of thebattery 2. The temperature detection part 144 detects, during chargingof the battery 2, the temperature of the battery 2. The temperaturedetection part 144 includes a temperature sensor capable of detectingthe temperature of the battery 2.

The temperature adjusting part 145 adjusts the temperature of thebattery 2 during the charge. Specifically, the temperature adjustingpart 145 adjusts the temperature of the battery 2 by performing heatingor cooling during charging of the battery 2. Methods of heating thebattery 2 include heating by charging itself and heating by a heater,for example. Methods of cooling the battery 2 include cooling by a fanor a compressor. The temperature adjusting part 145 adjusts thetemperature of the battery 2 during the charge such that the temperatureof the battery 2 becomes the target temperature, set by the targettemperature setting part 143, at the end of charging. That is, thetemperature adjusting part 145 heats or cools the battery 2 such thatthe temperature of the battery 2 detected by the temperature detectionpart 144 at the end of charging becomes the target temperature. By doingthis, the temperature of the battery 2 can be prevented from deviatingfrom the appropriate temperature zone even if the battery 2 is leftunattended after the end of charging. As a result, it is possible toprevent or protect the battery 2 from being adversely affected(deterioration or precipitation) due to the temperature of the battery 2deviating from the appropriate temperature zone after the end ofcharging.

<Charging Process for a Battery>

A charging process for the battery 2 will be described with reference toFIG. 4 .

FIG. 4 is a flowchart showing an example of a charging process for thebattery 2. First, the charge controller 10 determines whether or not tostart charging of the battery 2 (step S102).

When it is determined in step S102 that the charging of the battery 2 isto be started (Yes), the environment prediction part 142 predicts astate of the external environment of the vehicle 1 after the end ofcharging (step S104). For example, the environment prediction part 142predicts a change in an outside air temperature for a predetermined timefrom the end of charging.

Next, the target temperature setting part 143 sets a target temperatureof the battery 2 at the time of the end of charging on the basis of thepredicted state of the external environment (step S106). For example,the target temperature setting part 143 sets the target temperature onthe basis of a change in the outside air temperature after the end ofcharging.

Next, the temperature adjusting part 145 adjusts the temperature of thebattery 2 during the charge such that the temperature of the battery 2becomes the target temperature (step S108). For example, the temperatureadjusting part 145 heats or cools the battery 2 such that thetemperature of the battery 2 becomes the target temperature.

The charge control part 145 performs the process of step S108 untilcharging ends (step S110: Yes). Therefore, at the end of charging, thetemperature of the battery 2 becomes the target temperature.

<Effects of the Present Embodiment>

The charge controller 10 of the above-described embodiment predicts,during charging of the battery 2, a state of the external environmentafter the end of charging, and sets a target temperature at the end ofcharging on the basis of the predicted state of the externalenvironment. The charge controller 10 adjusts the temperature of thebattery 2 during the charge such that the temperature of the battery 2becomes the target temperature at the end of charging. By doing this, atemperature of the battery 2 at the end of charging reflects thepredicted state of the external environment. For example, when it ispredicted that the outside air temperature will rise after the end ofcharging, the temperature of the battery 2 at the end of chargingdecreases, and when it is predicted that the outside air temperaturewill decrease after the end of charging, the temperature at the end ofcharging of the battery 2 increases. Therefore, even if the battery 2 isleft unattended after the end of charging and the temperature of thebattery 2 changes due to the outside air temperature, temperatures inthe appropriate temperature zone can be easily maintained, and adverseeffects on the battery 2 can be prevented or reduced.

The present disclosure is explained on the basis of the exemplaryembodiments. The technical scope of the present disclosure is notlimited to the scope explained in the above embodiments and it ispossible to make various changes and modifications within the scope ofthe disclosure. For example, all or part the apparatus can be configuredwith any unit which is functionally or physically dispersed orintegrated. Further, new exemplary embodiments generated by arbitrarycombinations of them are included in the exemplary embodiments of thepresent disclosure. Further, effects of the new exemplary embodimentsbrought by the combinations also have the effects of the originalexemplary embodiments.

DESCRIPTION OF SYMBOLS

1 Vehicle

2 Battery

10 Charge controller

12 Storage

142 Environment prediction part

143 Target temperature setting part

145 Temperature adjusting part

1. A charge controller comprising: an environment prediction part that predicts, during charging of a battery mounted on a vehicle, a state of an external environment of the vehicle after an end of charging; a target temperature setting part that sets a target temperature of the battery at the end of charging on the basis of the state of the external environment predicted by the environment prediction part; and a temperature adjusting part that adjusts a temperature of the battery during the charge such that the temperature of the battery becomes the target temperature, set by the target temperature setting part, at the end of charging.
 2. The charge controller according to claim 1, wherein the environment prediction part predicts a change in an outside air temperature after the end of charging as the state of the external environment, and the target temperature setting part sets the target temperature on the basis of the change in the outside air temperature.
 3. The charge controller according to claim 2, wherein the environment prediction part predicts a magnitude of the change in the outside air temperature after the end of charging, and the target temperature setting part sets the target temperature within a predetermined temperature zone according to the magnitude of the change in the outside air temperature.
 4. The charge controller according to claim 2, wherein the target temperature setting part sets the target temperature lower than a predetermined value when the environment prediction part predicts that the temperature of the battery will rise after the end of charging, and sets the target temperature higher than the predetermined value when the environment prediction part predicts that the temperature of the battery will decrease after the end of charging.
 5. The charge controller according to claim 4, wherein the target temperature setting part sets the target temperature to a temperature at a lower limit in a predetermined temperature zone when the environment prediction part predicts that the temperature of the battery will rise after the end of charging, and sets the target temperature to a temperature at an upper limit in the temperature zone when the environment prediction part predicts that the temperature of the battery will decrease after the end of charging.
 6. The charge controller according to claim 1, wherein the charge controller further comprises a storage that stores environment information indicating a state of past external environment, and the environment prediction part predicts a state of an external environment after an end of charging on the basis of the environment information stored in the storage.
 7. The charge controller according to claim 1, wherein the temperature adjusting part adjusts the temperature of the battery during the charge by performing heating and cooling of the battery during charging of the battery.
 8. The charge controller according to claim 1, further comprising a temperature detection part that detects the temperature of the battery during the charge, wherein the temperature adjusting part adjusts the temperature of the battery during the charge such that the temperature detected by the temperature detection part at the end of charging becomes the target temperature. 